Assessing the removal efficiency of microplastics: A comparative study using nanosized biochars derived from sustainable sources

The industrial use of plastic materials has led to the production of microplastics, posing significant environmental risks. Microplastic pollution, especially in water systems, has prompted efforts to develop effective removal methods. Therefore, the purpose of this study is devoted to accomplish a novel comparative assessment analysis for the efficacy of two distinct nanosized biochars in removal of polystyrene microplastics (PS-MPs) from aquatic systems by using the batch removal mode. The two selected nanosized biochars, denoted as PAB-NB and AL-NB, were derived from the pyrolysis of pineapple peels and artichoke leaves, respectively. Characterization techniques confirmed the composition and surface properties of the nanobiosorbents. Results showed that both PAB-NB and AL-NB exhibited efficient removal of PS-MPs, with AL-NB demonstrating slightly higher removal capacity. Adsorption processes were found to follow Langmuir monolayer and Freundlich multilayer formations on PAB-NB and AL-NB, respectively. Kinetic studies suggested pseudo1st and pseudo-2nd order models for AL-NB and PAB-NB, respectively. At pH 2.0, both nanobiosorbents showed high removal rates, indicating neutralization of surface charges. These findings suggest that renewable nanobiosorbents derived from biomass wastes, free from metallic contaminants, hold promise for effective removal of polystyrene pollutants, offering a sustainable solution to prevent microplastic pollution in water systems.